Generally, a magnetic recording medium such as a magnetic tape and the like is produced by coating on a support a magnetic composition composed essentially of a magnetic powder, a resin binder and others, followed by drying. In such a magnetic recording medium, especially in a video tape, .gamma.-Fe.sub.2 O.sub.3, Co-.gamma.-Fe.sub.2 O.sub.3 and the like have been conventionally used as a magnetic powder, and it is a recent practice to use magnetic powders with smaller particle size in order to achieve higher S/N ratios. Further, Ba ferrite and metal powders have been used to meet a requirement for a higher density recording.
On the other hand, as described in Japanese Patent Publication Open to Public Inspection No. 60-124023/1985, a magnetic powder based on iron carbide is proposed. The iron carbide magnetic powder provides a high output at high Hc and an excellent conductivity and light-shielding property. However, a magnetic powder with finer particles (a BET value of over 40 m.sup.2 /g) for a higher density recording results in poor dispersibility of the particles especially of iron carbide, which in turn results in the inferior electromagnetic conversion characteristics of a magnetic recording medium, and further a durability in repetitive playing also deteriorates due to poor dispersibility.